The Life of the Fly 



twice as high ? Does she fear lest her worms 

 should be bruised by an excessive drop ? There 

 is nothing about her to point to anxiety- 

 aroused by the length of the shaft. I never 

 see her explore the tube or take its size. She 

 stands on the trellised orifice; and there the 

 matter ends. Can she be apprised of the 

 depth of the chasm by the comparative faint- 

 ness of the offensive odours that arise from it ? 

 Can the sense of smell measure the distance 

 and judge whether it be acceptable or not? 

 Perhaps. 



The fact remains that, despite the attraction 

 of the scent, the Flesh-fly does not expose her 

 worms to disproportionate falls. Can she 

 know beforehand that, when the chrysalids 

 break, her winged family, knocking with a 

 sudden flight against the sides of a tall chim- 

 ney, will be unable to get out? This fore- 

 sight would be in agreement with the rules 

 which order maternal instinct according to 

 future needs. 



But when the fall does not exceed a certain 

 depth, the budding worms of the Flesh-fly are 

 dropped without a qualm, as all our experi- 

 ments show. This principle has a practical ap- 

 plication which is not without its value in mat- 

 ters of domestic economy. It is as well that 

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